Recently, metals, metal compounds and metalloids have drawn attention as materials for use in various functional mechanisms and electronic devices. A reduction of impurities contained in these materials is desired because of the increase in performance characteristics now necessary. The same situation exists on oxygen content, and various devices to measure oxygen content or oxygen concentration in materials have been used pursuant to the increasing necessity of the reduction of impurities. Various devices have been used for the measurement of oxygen content or oxygen concentration in gases.
Two types of devices exist to measure the oxygen content or concentration in these materials or gases. One type of the devices measures the oxygen content or the oxygen concentration as an absolute value and the other type of device measures the oxygen content or the oxygen concentration as a relative value.
However, the device which measures absolute value involves not only complicated handling but also takes a long time to complete a measurement.
As the device which measures the relative value, there is in practical use, for instance, a device in which the oxygen contained in a sample or a gas is converted to carbon monoxide through a reaction with carbon, the carbon monoxide is changed to carbon dioxide by the use of an appropriate reagent and thereafter the quantity of the carbon dioxide is measured by infrared absorption or heat conduction. Since such a device yields a relative value, it always requires standard samples. Therefore, when the device is employed, the measured results can be wrong due to an error in the preparation of the standard samples. Moreover, in the range of a low oxygen concentration, the standard samples are difficult to prepare, and thus the measured results obtained by the device lack reliability.
Therefore, the object of the present invention is to provide an oxygen analyzer and an oxygen analyzing method which are free from the above-mentioned drawbacks of the conventional devices and can make a rapid and precise measurement of an oxygen content as an absolute value even in the range of a low oxygen concentration.